Flushing Coolant From Block

[Mid_Nite_R33]

hey guys,

I need to flush coolant from my rb25det and I been reading that to get to the drain plug its the biggest bitch, so would this work instead:

Unplug bottom and top radiator hoses and drainer the radiator

Assuming the bottom hose is the return and the top is feed to the engine, on a fully cold motor start ouring distilled water with a funnel into the top hose that's connected to the water inlet manifold and the block and run the motor for about 30 seconds, that way shit should come out out of the bottom return hose right?

any advice would be great,

Tom

[TRB-001]

disconnect one heater hose going to the firewall and take the cap off the radiator, flush with the hose in both directions.....

drain water out of radiator then fill with coolant mix via the heat hose to aid in faster bleeding times

[Galois]

im glad you asked tom because thats exactly what I was going to do!! where is the heating hose located?

thanks

[Mid_Nite_R33]

disconnect one heater hose going to the firewall and take the cap off the radiator, flush with the hose in both directions.....

drain water out of radiator then fill with coolant mix via the heat hose to aid in faster bleeding times

I have no idea where the heater hose is..?

im a bit confused, you're saying disconnect that heater hose and take off the radiator cap and then flush with a garden hose where the cap goes? keep both bottom and top main radiator hoses attached? engine running or off?

[Mid_Nite_R33]

im glad you asked tom because thats exactly what I was going to do!! where is the heating hose located?

thanks

Yea my coolant is embarrysingly filthy so draining the radiator is not enough as it only takes about 2.5L and the whole system carries 8.3L so therefore the block needs to be drained too, I've been reading quite a bit on all this and the drain plug for the block is a mission impossible so Im just thinking about other ways to flush the block. Anyway i spoke to a guy at repco and he didnt recomment to do what I described in my first post as the coolant (mud in my car) has a lot of pathways throught the engine and something could get clogged up, he recommended that I do two radiator flushes with the cleaning stuff or until the water becomes clear.....

Whats your opinion ?

[Wacky Dee]

dilute dilute dilute .. if it's really as dirty as you say, flush atleast 6-7 times by running the car until warmed up then unplug the drain on the radiator (near bottom hose) Use tap water to do that until it becomes clear, then put in your coolant mix.

Make sure that your heater is turned on full blast while doing it. Don't forget to bleed the air afterwards.

[Mid_Nite_R33]

dilute dilute dilute .. if it's really as dirty as you say, flush atleast 6-7 times by running the car until warmed up then unplug the drain on the radiator (near bottom hose) Use tap water to do that until it becomes clear, then put in your coolant mix.

Make sure that your heater is turned on full blast while doing it. Don't forget to bleed the air afterwards.

Yea thats the slow and painfull process haha, I was thinking of a way to flush the block somehow without undoing the block drain plug.... hmmm

Doesn't tap water cororde the engine, radiator etc..? I was told to only use distilled water....

[Wacky Dee]

It wont do any damage just for flushing purposes. One thing though and this is personal preference, don't use freezing cold tap water between flushes (when the engine is hot) I'd put warm tap water in when flushing.

What I did to mine was as suggested above and then i diluted the water in the system by flushing another 5 times or so with (premixed) coolant until I was certain it was only the coolant mix left in there at the correct concentration.

[Mid_Nite_R33]

It wont do any damage just for flushing purposes. One thing though and this is personal preference, don't use freezing cold tap water between flushes (when the engine is hot) I'd put warm tap water in when flushing.

What I did to mine was as suggested above and then i diluted the water in the system by flushing another 5 times or so with (premixed) coolant until I was certain it was only the coolant mix left in there at the correct concentration.

Yea Im totally aware of not putting cold water to a hot engine issue.

So maybe the first few flushes ill do with just water and say the last two ill do with some cheap coolant premix so that at the end of all the flushings I'll end up with coolant in the block, right? and then on the final coolant fill I'll put in the 100 grade stuff and should all even out?

[Wacky Dee]

never mix 2 different coolants though.

10l of the 30% premixed Nulon coolant costs about $20 .. just buy 2.

[TRB-001]

ok ill explain it. your heater hoses are two small hoses that connect to the fire wall on the passenger side of the engine. they are medium size hoses, abit bigger then the diameter of your thumb. undo one hose (by loosing clamp) and pull it off the connector on the firewall. take put the garden hose into the coolant hose u just pulled off, block off the plastic connector the hose was connected too (with your hand or a rag). take off the radiator cap and turn the hose on.... the water will go thru the complete system and come out your radiator top.

to that til it runs clear for awhile, then switch the garden hose, block off the rubber coolant hose with your hand and put the garden hose onto the firewall connection and turn it on til it runs clear.

finally keep ur finger on the coolant hose, put the garden hose in the radiator and turn it on, watch the water coming out of the firewall until its clear. run it til its hot. drain the radiator and add coolant mixture.

if it is still dirty after this process, go to kmart, by some radiator flush and follow the instructions... and flush as per above instructions and refill with the correct coolant mixture.

[Mid_Nite_R33]

ok ill explain it. your heater hoses are two small hoses that connect to the fire wall on the passenger side of the engine. they are medium size hoses, abit bigger then the diameter of your thumb. undo one hose (by loosing clamp) and pull it off the connector on the firewall. take put the garden hose into the coolant hose u just pulled off, block off the plastic connector the hose was connected too (with your hand or a rag). take off the radiator cap and turn the hose on.... the water will go thru the complete system and come out your radiator top.

to that til it runs clear for awhile, then switch the garden hose, block off the rubber coolant hose with your hand and put the garden hose onto the firewall connection and turn it on til it runs clear.

finally keep ur finger on the coolant hose, put the garden hose in the radiator and turn it on, watch the water coming out of the firewall until its clear. run it til its hot. drain the radiator and add coolant mixture.

if it is still dirty after this process, go to kmart, by some radiator flush and follow the instructions... and flush as per above instructions and refill with the correct coolant mixture.

ok instead of having it pour of the radiator top and making a big mess can i just undo the bottom radiator hose so it can all flush out from there?

also u during the flushing process is the engine on or off?

thanks heaps!

[mad082]

also if you coolant is dirty (brown) then you might want to think about getting the radiator cleaned (or just replacing it as the cost isn't much different) as you can get quite a bit of build up in the core which can block it and reduce it's performance.

[Mid_Nite_R33]

also if you coolant is dirty (brown) then you might want to think about getting the radiator cleaned (or just replacing it as the cost isn't much different) as you can get quite a bit of build up in the core which can block it and reduce it's performance.

Yea exactly , I was considering this aluminium radiator Ebay job which is meant to be a direct fit, u think its worth it?:

http://cgi.ebay.com.au/ws/eBayISAPI.dll?Vi...e=STRK:MEWAX:IT

If I was to get that, at which stage do I install it, first do the flushes and block cleaning as explained above with the old radiator still on and then chuck on the new one right?

tom

[mad082]

i'd do the flusing first.

but to flush it i would simply wait till the car is dead cold, drop the coolant, remove the thermostat and then jam a hose into the top hose and let it run for a while.

[Ruffels]

bit of work, but best way is to remove the waterpump, shove hose up the guts, turn on hose full blast,

[Mid_Nite_R33]

i'd do the flusing first.

but to flush it i would simply wait till the car is dead cold, drop the coolant, remove the thermostat and then jam a hose into the top hose and let it run for a while.

where is the thermo stat and whats it look like? you mean put a hose into the top radiator hose?

so many questons, by its my first coolant change ever haha!

[mad082]

the thermostat is in the top hose where the hose meets the block. there will be a fitting the hose goes onto which is bolted to the block with 3 bolts. behind that is the thermostat.

with the thermostat in and the engine cold it will stay shut and won't let any water past, so jamming a hose in either of the radiator hoses won't do much, so you need to pull it out to allow the water to flow past it. depending on the type of thermostat that is fitted it may even be holding the water in the block in the same way that you can pick up water with a straw by blocking the top of it.

[evers]

any of use wouldnt happen to no where i can get the part labled 14875PA in the diagram below would you? Mine is busted and leaks coolant everywere.

Cheers

[Mid_Nite_R33]

the thermostat is in the top hose where the hose meets the block. there will be a fitting the hose goes onto which is bolted to the block with 3 bolts. behind that is the thermostat.

with the thermostat in and the engine cold it will stay shut and won't let any water past, so jamming a hose in either of the radiator hoses won't do much, so you need to pull it out to allow the water to flow past it. depending on the type of thermostat that is fitted it may even be holding the water in the block in the same way that you can pick up water with a straw by blocking the top of it.

Oh i see, so I gotta pull that thermostat out before flushing the bkock to sort of unplug the block in a way?

Also how can I tell the condition of the thermostat?, might as well replace it while im at it if need be...

much appreciated,

tom